azure-web-pubsub-ts

Azure Web PubSub SDKs for TypeScript

Real-time messaging with WebSocket connections and pub/sub patterns.

Installation

# Server-side management
npm install @azure/web-pubsub @azure/identity

# Client-side real-time messaging
npm install @azure/web-pubsub-client

# Express middleware for event handlers
npm install @azure/web-pubsub-express

Environment Variables

WEBPUBSUB_CONNECTION_STRING=Endpoint=https://<resource>.webpubsub.azure.com;AccessKey=<key>;Version=1.0;
WEBPUBSUB_ENDPOINT=https://<resource>.webpubsub.azure.com

Server-Side: WebPubSubServiceClient

Authentication

import { WebPubSubServiceClient, AzureKeyCredential } from "@azure/web-pubsub";
import { DefaultAzureCredential } from "@azure/identity";

// Connection string
const client = new WebPubSubServiceClient(
  process.env.WEBPUBSUB_CONNECTION_STRING!,
  "chat"  // hub name
);

// DefaultAzureCredential (recommended)
const client2 = new WebPubSubServiceClient(
  process.env.WEBPUBSUB_ENDPOINT!,
  new DefaultAzureCredential(),
  "chat"
);

// AzureKeyCredential
const client3 = new WebPubSubServiceClient(
  process.env.WEBPUBSUB_ENDPOINT!,
  new AzureKeyCredential("<access-key>"),
  "chat"
);

Generate Client Access Token

// Basic token
const token = await client.getClientAccessToken();
console.log(token.url);  // wss://...?access_token=...

// Token with user ID
const userToken = await client.getClientAccessToken({
  userId: "user123",
});

// Token with permissions
const permToken = await client.getClientAccessToken({
  userId: "user123",
  roles: [
    "webpubsub.joinLeaveGroup",
    "webpubsub.sendToGroup",
    "webpubsub.sendToGroup.chat-room",  // specific group
  ],
  groups: ["chat-room"],  // auto-join on connect
  expirationTimeInMinutes: 60,
});

Send Messages

// Broadcast to all connections in hub
await client.sendToAll({ message: "Hello everyone!" });
await client.sendToAll("Plain text", { contentType: "text/plain" });

// Send to specific user (all their connections)
await client.sendToUser("user123", { message: "Hello!" });

// Send to specific connection
await client.sendToConnection("connectionId", { data: "Direct message" });

// Send with filter (OData syntax)
await client.sendToAll({ message: "Filtered" }, {
  filter: "userId ne 'admin'",
});